Answer:
According to Darwin's theory of evolution, new species evolved as a result of natural selection.
Explanation:
- Darwin proposed that speciation could readily occur through the prolonged action of Natural selection.
- Natural selection allows the 'survival of the fittest' i.e. a more fit organism will have a better chance of survival than the less fit one.
- The result of Natural selection could be positive,negative or balancing.
- Evolutionary process in which the genetic changes confer a higher fitness to increase frequency of the organism over time in population is called positive selection.
- Evolutionary process in which genetic changes decreases the organism's fitness resulting in its disappearance from the population is called Negative selection.
- It may happen that a mutation benefits hetero-zygotes but not homo-zygotes and alleles maintain a intermediate frequency in population.This evolutionary process is called balancing selection.
What alleles do the parents have? If the parents are both Homozygous recessive the answer is 0%. If one is homozygous dominant it doesn't matter what the other one is, the answer is 100%. if the are both heterozygous the answer is 75%
Answer:
C) Through genomic imprinting, methylation regulates expression of the paternal copy of the gene in the brain.
Explanation:
The pattern of gene expression wherein either paternal or maternal gene is expressed in specific cells while the other one is prevented from expression is known as genomic imprinting.
In the given example, the maternal copy of the gene on chromosome 15 is expressed in brain cells while its paternal copy is not expressed in these cells. Hence, the pattern of expression of this gene is regulated through genome imprinting. One of the mechanism is methylation of cytidine residues of CpG islands of the DNA that are more frequently present within promoters of the genes.
When the cytidine residues of these sequences are methylated into 5-methylcytidine, the transcription factors do not bind to these promoters preventing the expression of these genes.
Hence, methylation of cytidine residue in CpG islands of the promoters of the gene present on chromosome 15 could have silenced its expression in brain cells.
C, if you look at a water wheel, water flows on the wheel, turning a rod, powering something on the inside. Dams do the same thing except the rod goes into a transformer and is more complicated.
Answer: A line graph would be the best graph to show trends in data
Explanation:
